A 31-year-old man, who was arrested on July 28 on suspicion of attempted murder, has been released under investigation.

The £10,000 reward is being offered by police for information leading to the conviction of the culprit - or culprits - and/or the recovery of the firearm.

Detective Constable Shaun Pascal, of the Metropolitan Police's Trident and Area Crime Command, said: "This was a deplorable shooting at a children's barbecue, which left the victim with serious injuries. It is believed he will make a full recovery but the long-term effects will haunt him for many years to come.

"There are members of the public who attended the barbecue and may have witnessed this incident who could have a vital piece of information to help us piece together what happened.

"Any statements made to police will be treated in confidence. I would urge any witnesses with any information about this incident to contact us so we can bring those responsible for this crime to justice."

Anyone with any information is asked to call Trident detectives on 020 8217 7382 or Crimestoppers, anonymously, on 0800 555111.